Modern locks fall into three major classifications according to application: A rim lock is applied to the surface of a door or drawer. A mortise lock is inserted in a precut cavity which has been prepared for it. A portable lock is a temporary locking device that does not become a permanent part of the structure on which it serves.
Locks may also be designated by use, that is, automobile lock, suitcase lock, panic or exit lock, coinbox lock, bicycle lock, telephone lock and many others. However, most suitcase locks on the market are undesirable. For the purpose of overcoming the drawbacks of the suitcase locks on the market, the present inventor has made a lock constituted by a combination lock and a key-type lock so that the combined lock may still be opened without being impaired, and the correct numbers of the combination lock can be found out by a decoding rod.